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authorRobin Murphy <robin.murphy@arm.com>2023-06-01 19:43:33 +0300
committerWill Deacon <will@kernel.org>2023-06-09 00:00:22 +0300
commit6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d (patch)
treeb0db137e9f9da58d5234aeb419a97fab72d4d752 /drivers/iommu
parent0bfbfc526c70606bf0fad302e4821087cbecfaf4 (diff)
downloadlinux-6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d.tar.xz
iommu/arm-smmu-v3: Set TTL invalidation hint better
When io-pgtable unmaps a whole table, rather than waste time walking it to find the leaf entries to invalidate exactly, it simply expects .tlb_flush_walk with nominal last-level granularity to invalidate any leaf entries at higher intermediate levels as well. This works fine with page-based invalidation, but with range commands we need to be careful with the TTL hint - unconditionally setting it based on the given level 3 granule means that an invalidation for a level 1 table would strictly not be required to affect level 2 block entries. It's easy to comply with the expected behaviour by simply not setting the TTL hint for non-leaf invalidations, so let's do that. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/b409d9a17c52dc0db51faee91d92737bb7975f5b.1685637456.git.robin.murphy@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index bbad54aa6c8c..bbafb9639e5a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1898,8 +1898,13 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
/* Convert page size of 12,14,16 (log2) to 1,2,3 */
cmd->tlbi.tg = (tg - 10) / 2;
- /* Determine what level the granule is at */
- cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
+ /*
+ * Determine what level the granule is at. For non-leaf, io-pgtable
+ * assumes .tlb_flush_walk can invalidate multiple levels at once,
+ * so ignore the nominal last-level granule and leave TTL=0.
+ */
+ if (cmd->tlbi.leaf)
+ cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));
num_pages = size >> tg;
}